import java.util.Scanner;

public class suo {
    public static void main(String[] arg){
        int []arr = {19,28,37,46,50};
        Scanner reader = new Scanner(System.in);
        System.out.println("请输入一个数据：");
        int x = reader.nextInt();
        int y = -1;
        for (int i=0;i<arr.length;i++){
            if (y==arr[i]){
                y = i;
                System.out.println("索引值为："+y);
            }else {
                System.out.println("输入有误");
            }
        }
        System.out.println();
    }
}
